Although we are two years away from the first ballot being cast in the 2008 presidential election and don't even know who the candidates will be, we already know a great deal about how the race will turn out. Historical trends tell us that the Republican candidate will be very tough to beat regardless of who he is.

To see why this is the case, let's first look at which states voted for George W. Bush in both 2000 and 2004, and those that went for both Al Gore and John Kerry. This will give us a good guide to each party's base.

Starting with Bush, we see that he carried all of these states twice: Alabama, Alaska, Arizona, Arkansas, Colorado, Florida, Georgia, Idaho, Indiana, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Montana, Nebraska, Nevada, North Carolina, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, West Virginia and Wyoming. They have 274 electoral votes, with 270 needed to win.

In 2000, Iowa and New Mexico went for Gore and switched to Bush in 2004. New Hampshire went for Bush in 2000, but went for Kerry in 2004. These three states are the only ones that changed party, and the vote shift was very small. In 2000, Gore won Iowa with 48.54 percent of the vote to 48.22 percent for Bush; in 2004, Bush won the state with 49.9 percent to Kerry's 49.23 percent.

A similar story is told in New Hampshire and New Mexico. Bush carried the Granite State with 48.07 percent of the vote to 46.8 percent for Gore in 2000; in 2004, Kerry got 50.24 percent to 48.87 percent for Bush. New Mexico gave Gore 47.91 percent of the vote in 2000 to Bush's 47.85 percent. In 2004, Bush took the Land of Enchantment with 49.84 percent to 49.05 percent for Kerry.

Looking at potential swing states, we see that Bush won the following states in 2000 with less than 50 percent of the vote: Florida, Nevada, New Hampshire and Ohio. Gore won these states with less than 50 percent: Iowa, Maine, Minnesota, New Mexico, Oregon and Wisconsin. But in 2004, there were only three states that were won with less than 50 percent of the vote: Iowa and New Mexico went for Bush, and Wisconsin went for Kerry.

Interestingly, one of the major factors helping Bush in 2004 over 2000 wasn't a change in voting, but a shift in population. The 2000 census awarded seven additional electoral votes to the states he carried twice, with the same number being subtracted from those that went for Gore and Kerry. Among Bush's states, Arizona, Florida, Georgia and Texas each picked up two additional electoral votes. Colorado, Nevada and North Carolina gained one apiece. Indiana, Mississippi, Ohio and Oklahoma each lost a vote.

Looking at the Democrats, only California and the District of Columbia gained an electoral vote between 2000 and 2004. New York and Pennsylvania lost two votes each. Connecticut, Illinois, Michigan, Minnesota and Wisconsin lost one apiece.

What this means is that if the population distribution in 2000 had been reflected in the Electoral College that year, Bush would have won 278 electoral votes instead of the 271 he was officially awarded, and Gore would have had 259 votes instead of the 266 he got. If the final electoral vote had been 278 to 259 instead of the actual 271 to 266, much of the rancor over the results might have been avoided.

The 2010 census is likely to accelerate the Republican advantage. According to preliminary estimates by Polidata.org, 13 electoral votes will probably shift before the 2012 election. States that Bush carried twice will gain another seven net electoral votes, and those carried by Gore and Kerry will lose six net seats.

States expected to gain electoral votes include Arizona (+2), Florida (+2), Georgia (+1), Nevada (+1), Oregon (+1), Texas (+4), Utah (+1) and Washington (+1). Losing states are Illinois (-1), Iowa (-1), Louisiana (-1), Massachusetts (-1), Michigan (-1), Minnesota (-1), Missouri (-1), New Jersey (-1), New York (-2), Ohio (-2) and Pennsylvania (-1). All the gaining states went for Bush twice except for Oregon and Washington. All of the losing states went for Gore and Kerry except Iowa, Louisiana, Missouri and Ohio.

Internet betting sites, such as Intrade.com, see the Democrats having about a 55 percent chance of winning in 2008. However, for him or her to win, they will have to get a good-sized state that went for Bush twice to switch. That may be hard.